The development of efficient and economical systems and techniques for the passive heating and cooling of buildings and other structures has become increasingly important in recent years. A number of devices and methods have been developed for harnessing heat energy from the sun and utilizing that heat for hot water or space heating purposes. Several of these devices utilize a thermal mass or fluid for receiving and storing radiant energy from the sun. Some such devices rely on natural thermosiphoning for creating convection currents in which the warmer fluid rises and the cooler fluid sinks.
For example, one conventional method of heating hot water by solar energy utilizes a thermosiphoning system in which a solar collector is located below a water storage tank. The top of the collector is connected to the top of the storage tank, and the bottom of the collector is connected to the bottom of the storage tank so that heated water from the collector may rise as a result of its lower density into the storage tank, and cooler water may sink to the bottom of the storage tank and return to the bottom on the collector. In such a system, there is a thermosiphoning circulation during the day in which hot water is continually flowing from the top of the collector to the top of the storage tank. After dark, the less dense heated water remains at the top of the storage tank and is available for hot water or heating use.
The thermosiphoning principle has also been applied to systems in which the solar collector is located on the same level as the water storage device. Generally, these devices include a valve arrangement for preventing reverse thermosiphoning at night. Examples of such devices are shown in U.S. Pat. Nos. 4,050,508 and 4,245,617 to Buckley, 4,149,589 to Hoffman, and 4,290,416 and 4,294,229 to Maloney, the named inventor herein.
Although earlier designs in solar heating devices generally required exterior mounting on the roof of a building or structure, more recent designs have placed emphasis on devices which can be installed directly in the wall or roof frame structure of the building. However, such devices have not been readily accepted commercially by builders and other developers because of their high cost, the difficulty of incorporating such devices into standard housing plans, and the adverse visual and esthetic impact on the overall house design perceived by the majority of home buyers. In addition, the difficulty of installing the necessary components and plumbing elements in the narrow space provided by a building frame has generally prevented the commercial acceptance of the above-described solar heating devices. In addition, the anti-reversing valves and other innerconnections required in such devices have proven to be difficult and costly to manufacture.
Numerous attempts have also been made in the prior art to increase the efficiency of solar heating devices. Typically, the efficiency of a solar heating system will be a function of the ability to collect and store heat while limiting the losses of heat from the building or structure. One approach to this problem has been the use of movable insulation devices which limit nighttime losses by shielding the solar collection area. However, the use of movable insulation is expensive, involves interference with interior design and requires daily operation and access to the system.
Accordingly, it is a primary object of this invention to increase the efficiency of solar heating devices.
It is a further object of this invention to provide a solar heating device which is both highly efficient and economical to manufacture.
Another object of the invention is to allow installation of a solar heating device directly in the exterior frame of a building without significantly modifying the aesthetic lines of the building and to blend the device aesthetically with other building materials.
An additional object of the invention is to eliminate the need for cumbersome and space-consuming plumbing connections between the collection and storage areas in a solar heating device.
It is a further object of the invention to provide a passive means for cooling a building which is economical to manufacture and simple to install.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice of the invention.